WitrynaSynthesis and Imidization of Biphenylic Dianhydride–Oxydianiline-Based Isomeric Poly(amic methyl ester)s WENXI HUANG, MENGXIAN DING Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Witryna21 wrz 2024 · Polyimide is an organic polymer that exhibits the highest level of heat resistance, exhibits excellent mechanical properties and electrical insulation, and is stable for a long period of time. In addition, since it is easy to obtain polymers with different physical characteristics by changing the combination of monomers, it is possible to …
Synthesis of poly [ (amic acid)-co- (amic ester)] precursors …
Witryna1 cze 1997 · The cure behaviour of the ethyl ester derivatives of 4,4′-oxydianiline (ODA)/pyromellitic dianhydride (PMDA) poly(amic acid) to the corresponding imid… Witrynaa highly viscous poly(amic acid) (PAA) solution was obtained. Second, poly(amic acid) is converted to polyimide by either thermal or chemical imidization. Since poly (amic … inception produced by
Poly(ortho Ester) - an overview ScienceDirect Topics
Witrynapoly(amic acid) due to the nucleophilic attack of the amino group on the carbonyl carbon of the anhydride group. The scheme that is illustrated in Figure 1.2 involves a reversible reaction leading to opening of the anhydride ring to form an amic acid group5. However, the forward rate constant for the reaction is several orders of magnitude larger Witrynamation of many reactive impurities from excipients is proposed to occur by oxidative mechanisms.14–16 Peroxides and metal ion impurities can lead to free-radical-initiated oxidation reactions, which are be-lieved to be responsible for the formation of reactive impurities such as low-molecular-weight aldehydes and organic acids in PEG.14,17–20 Witryna1 sie 1997 · Para—para linked aromatic poly(amic ester) precursors of rodlike polyimide (PI) BPDA-PDA and polyetherimide (PEI) HQDPA-ODA were synthesized. The para… income summary my gov